This is a quick tutorial to help find information quickly using tcpdump. I'm not going to get into explaining everything just some quick commands to find what you are looking for.
Capture HTTPS Traffic
tcpdump -nnSX port 443
NOTE: You can use the same command to capture any traffic, just change the port
21:57:41.587391 IP 10.11.24.11.60394 > 126.96.36.199.443: Flags [S], seq 2618307083, win 29200, options [mss 1460,sackOK,TS val 1261029685 ecr 0,nop,wscale 7], length 0
In the environment I work in we have multiple firewalls in a path so the likely of your traffic being blocked is high. Most of us use to troubleshoot using telnet which has many many flaws and not a great method of testing but it was all we had.
Here is an example of testing using telnet
telnet: 10.11.24.11:80: Name or service not known
10.11.24.11:80: Unknown host
The telnet results don't really give you anything to tell you if its successful or not.